Try building 1,500 miles of four-lane highway from the end of the Kolyma Road to the easternmost tip of Siberia, and the infrastructure to support it and the traffic year-round, to anything resembling an acceptable standard to American or European users.
Then try extending the Trans-Siberian Railroad to link up with a new railway in Alaska. Differing gauges would be the least of problems.
Then try building the bridge itself to withstand the heaviest ice and coldest temperatures any bridge has been subjected to.
I can think of a hundred different hurdles before the first shovel goes into the ground.